[76Miller]

Bassett offers a 2 1/2'' and the common 2 1/4'' when do you step up ??? If the motor is n/a and not blown is there any gains with the bigger primary ???? has anybody tested this on a dyno ??

 

[vee-driven]

i would say 2 1/4 with a n/a motor, because i think a little back pressure would be good.

 

[Brad22CP]

What cubic inch?

 

[Rexone]

2 1/4 will yield more HP on most any N/A engine unless it's a prostock or something very radical. 1 7/8" or 2" actually works better on most but they don't offer them any more since water injection came about.

 

[76Miller]

i would say 2 1/4 with a n/a motor, because i think a little back pressure would be good.

Pat, your probably right. I was hoping maybe somebody has tested it before I buy another set of 2 1/4'' .

 

[76Miller]

What cubic inch?

Its a 533ci. n/a jet boat.

 

[76Miller]

2 1/4 will yield more HP on most any N/A engine unless it's a prostock or something very radical. 1 7/8" or 2" actually works better on most but they don't offer them any more since water injection came about.

Rex, have you actually tested this ??? Does more exhaust "scavaging" take place with the smaller pipe ? Just figured if there is gains to be made, the price difference is not much.

 

[Rexone]

Rex, have you actually tested this ??? Does more exhaust "scavaging" take place with the smaller pipe ? Just figured if there is gains to be made, the price difference is not much.

I have not personally but have spoken with many who have over the years. 2" is generally considered about optimum (dry). When you add water 2 1/4" seems to work good. Note that all engines are different. If you have huge cam and heads you may need something larger. 2 1/2" on most N/A engines though would be considered too big. Only the dyno knows for sure on this though.

 

[lebel409]

On a 409 1 7/8" seems optimum...2" looses power until over 6K rpm.